Featured Research

from universities, journals, and other organizations

Blood test accurately detects lymphedema, study shows

Date:

December 18, 2012

Source:

Stanford University Medical Center

Summary:

Scientists have identified a set of proteins circulating in blood whose levels accurately flag the presence of lymphedema. The findings spur optimism that this common but relatively neglected condition, which affects an estimated 10 million people in the United States, finally will be amenable to detection (and, eventually, treatment) with 21st-century techniques.

Share This

Scientists at the Stanford University School of Medicine have identified a set of proteins circulating in blood whose levels accurately flag the presence of lymphedema. The findings, reported Dec. 18 in PLoS ONE, spur optimism that this common but relatively neglected condition, which affects an estimated 10 million people in the United States, finally will be amenable to detection (and, eventually, treatment) with 21st-century techniques.

Related Articles

Lymphedema is an often-painful inflammatory condition resulting from the blockage of lymphatic vessels that ordinarily drain fluid from the tissues throughout the body. In the developed world, lymphedema most often arises as an unintended consequence of radiation therapy for cancer. For example, about one in four breast-cancer survivors eventually develops lymphedema, said Stanley Rockson, MD, professor of cardiovascular medicine and the study's senior author. Numerous other factors, including parasitic infections endemic in some developing countries, can cause it as well, he said.

The blunting of normal immune-cell flow due to lymphatic-vessel blockage helps to trigger the buildup of fluid within the affected area of the body, along with thickening of the skin, profound inflammation, accumulation of fibrous tissue, excessive blood-vessel formation and a marked expansion of the fatty layer beneath the skin.

By the time the main symptom -- swelling of one or more limbs -- is detectable, the condition may have gotten such a foothold that it becomes difficult or impossible to reverse, at least given current treatment options, Rockson said.

The only known way to diagnose lymphedema now is via physical inspection, and all too often it is misdiagnosed or overlooked altogether. But the biological events underpinning this condition may be present five years or more before symptoms become evident, said Rockson. Moreover, there are no effective drugs for combating lymphedema, just costly, time-consuming and annoying physical therapy, which virtually never completely eliminates the symptoms. While physical therapy can arrest progression and reduce swelling by as much as half, the condition typically remains a long-term problem. "Lymphedema virtually never just goes away on its own," said Rockson. Indeed, it tends to progress in severity over time, whether it is treated or not.

The irreversible skin thickening, joint immobility, scarring, increased susceptibility to infection and other consequences of chronic lymphedema can leave patients discomfited for life, all too often resulting in social withdrawal, body-image deterioration and other quality-of-life issues. "This is especially ironic in the case of cancer survivors who have endured difficult life-saving interventions, only to find that now cured, they're unable to enjoy their lives," said Rockson, who is the Allan and Tina Neill Professor of Lymphatic Research and Medicine and chief of consultative cardiology at the medical school.

For this study, Rockson and his associates obtained skin-biopsy samples from both lymphedematous and normal tissue of 27 patients. Using advanced molecular methods, they compared each patient's diseased tissue with that same patient's healthy tissue to see which genes -- the recipes for the myriad proteins produced in our bodies -- were more actively engaged in the generation of their respective protein products in diseased versus healthy tissue. Thousands of genes fit the bill. Then the investigators narrowed their search to the overproduced proteins themselves, in particular ones that were already known to circulate throughout the bloodstream of all people, including healthy ones, and for which fast, commercial blood tests already exist.

Statistical modeling indicated a panel of tests that measured six separate proteins' levels in study subjects' blood was able to distinguish the lymphedematous patients from control subjects who did not have lymphedema. None of these six proteins was predictive by itself. But in aggregate, their presence at certain levels and ratios appeared to serve as a biological fingerprint, or biomarker, for lymphedema.

Interestingly, all six proteins are well-known, and each is associated with one or another of chronic lymphedema's hallmark biological features: accumulation of fibrous deposits, stimulation of fat-cell activity, inflammation and lymphatic-vessel formation and repair. "These biomarkers may themselves lead us to valuable pharmaceutical targets," said Rockson.

To determine their six-protein biomarker-panel's validity, Rockson's group collected blood from a new cohort of 36 lymphedematous and 15 healthy adults, extracted blood samples and tested them with the panel. The test distinguished those with lymphedema from healthy subjects with an accuracy approaching 90 percent -- good enough for use as a clinical diagnostic tool and a vast improvement over current detection methods, said Rockson.

"This is a significant development," he said.

Because levels of the six proteins begin to climb early in the course of the disease, such a test should be valuable in determining risk for, or the onset of, lymphedema long before symptoms occur -- which in turn would mean earlier, appropriate therapeutic intervention, perhaps in time to spare patients from the condition's most-damaging effects or even reverse its course.

"In addition," Rockson said, "a standardized, accurate bioassay for lymphedema could help to pave the road for future human clinical trials of drugs to treat it." Monitoring trial subjects at the molecular level with a lymphedema-detecting blood test could provide early evidence regarding whether an experimental treatment is working. Rockson is involved in conducting clinical trials of pharmaceutical agents for lymphedema, and hopes to use the new test in those trials.

More From ScienceDaily

More Health & Medicine News

Featured Research

Mar. 3, 2015 — Limp or firm, your handshake conveys subliminal social cues. Now, research reveals it also transmits chemical signals that could explain why the greeting evolved in the first ... full story

Mar. 3, 2015 — Two of the four known groups of human AIDS viruses (HIV-1 groups O and P) have originated in western lowland gorillas, according to new research. The scientists conducted a comprehensive survey of ... full story

Mar. 2, 2015 — In the first study of its kind since the 1920s, rats in New York City were found to carry a flea species capable of transmitting plague pathogens. Among them: 500-plus Oriental rat fleas, notorious ... full story

Mar. 2, 2015 — A newly published study is the first to report an association between bisphenol-A (BPA), a common plasticizer used in a variety of consumer food and beverage containers, with autism spectrum disorder ... full story

Mar. 2, 2015 — What do a human colon, septic tank, copper nanoparticles and zebrafish have in common? They were the key components used by researchers to study the impact copper nanoparticles, which are found in ... full story

Mar. 2, 2015 — You might resemble or act more like your mother, but a novel research study reveals that mammals are genetically more like their dads. Specifically, the research shows that although we inherit equal ... full story

Mar. 2, 2015 — Scientists who have discovered the mechanism of a protein that suppresses inflammation in the body, say the information could potentially be used to develop new drugs to control inflammation. The ... full story

Mar. 2, 2015 — A deficiency in the protein responsible for moving glucose across the brain's protective blood-brain barrier appears to intensify the neurodegenerative effects of Alzheimer's disease, according to a ... full story

Mar. 2, 2015 — Researchers describe how postmortem brain slices can be 'read' to determine how a rat was trained to behave in response to specific sounds, a new article suggests. The work provides one of the first ... full story

Mar. 2, 2015 — Teenagers in North Carolina were easily able to buy electronic cigarettes online because both Internet vendors and shipping companies failed to verifying ages in a study that assessed compliance with ... full story

Featured Videos

Mom Triumphs Over Tragedy, Helps Other Families

AP (Mar. 3, 2015) — After her son, Dax, died from a rare form of leukemia, Julie Locke decided to give back to the doctors at St. Jude Children&apos;s Research Hospital who tried to save his life. She raised $1.6M to help other patients and their families. (March 3)
Video provided by AP

Woman Convicted of Poisoning Son

AP (Mar. 3, 2015) — A woman who blogged for years about her son&apos;s constant health woes was convicted Monday of poisoning him to death by force-feeding heavy concentrations of sodium through his stomach tube. (March 3)
Video provided by AP

Related Stories

Oct. 3, 2014 — A new study may lead to earlier detection and better outcomes for the 20-30 percent of breast cancer patients with lymphedema, the painful and stigmatizing arm swelling that often results from ... full story

Nov. 12, 2013 — Now, a team of researchers offers supporting evidence for using Bioelectrical Impedance Analysis (BIA) ratios to assess Lymphedema. The study argues because the low frequency electronic current ... full story

Dec. 1, 2011 — Lymphedema, a chronic swelling condition common in breast cancer survivors, affects three million people in the US. In the past, most people believed that exercise might induce or worsen lymphedema. ... full story

Sep. 5, 2011 — Researchers have discovered a gene that when mutated can cause lymphedema (swollen limbs due to a failure of the lymph system), immune abnormalities, deafness and leukemia. The identification of the ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.